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Abstract:

A luminescent element is disclosed including: a luminescent substrate;
and a metal layer with a metal microstructure formed on a surface of the
luminescent substrate; wherein the luminescent substrate comprises a
luminescent material with a chemical composition of Y2SiO5:Tb.
A preparation method of a luminescent element and a luminescence method
are also provided. The luminescent element has good luminescence
homogeneity, high luminescence efficiency, good luminescence stability
and simple structure, and can be used in luminescent devices with
ultrahigh brightness.

Claims:

1. A luminescent element, comprising: a luminescent substrate; and a
metal layer with a metal microstructure formed on a surface of the
luminescent substrate; wherein the luminescent substrate comprises a
luminescent material with a chemical composition of Y2SiO5:Tb.

2. The luminescent element according to claim 1, wherein the luminescent
substrate is a luminescent glass doped with the luminescent material with
a chemical composition of Y2SiO5:Tb; the luminescent glass has
a composition of 20Na2O-20BaO-30B2O3-30SiO.sub.2.

3. The luminescent element according to claim 2, wherein the luminescent
material of Y2SiO5:Tb is 5%˜35% by weight of the
luminescent substrate.

4. The luminescent element according to claim 1, wherein the luminescent
substrate comprises a transparent or translucent substrate and a
luminescent film formed on the substrate with a chemical composition of
Y2SiO5:Tb, and the metal layer is formed on a surface of the
luminescent film.

5. The luminescent element according to claim 1, wherein the metal layer
is made of at least one metal selected from the group consisting of Au,
Ag, Al, Cu, Ti, Fe, Ni, Co, Cr, Pt, Pd, Mg, and Zn.

6. The luminescent element according to claim 1, wherein the metal layer
has a thickness in a range of 0.5.about.200 nm.

7. A preparation method of a luminescent element, comprising: preparing a
luminescent substrate comprising a luminescent material with a chemical
composition of Y2SiO5:Tb; forming a metal layer on a surface of
the luminescent substrate, and annealing the luminescent substrate and
the metal layer in vacuum to form a metal microstructure of the metal
layer, and then cooling the luminescent substrate and the metal layer to
form the luminescent element.

8. The preparation method according to claim 7, wherein the preparation
of the luminescent substrate comprises: mixing the luminescent material
of Y2SiO5:Tb and glass powder; melting the luminescent material
of Y2SiO5:Tb and glass powder at a temperature in a range of
1000.about.1300.degree. C.; cooling the luminescent material of
Y2SiO5:Tb and glass powder to ambient temperature, and
obtaining the luminescent glass doped with the luminescent material of
Y2SiO5:Tb; wherein the luminescent glass has a composition of
20Na2O-20BaO-30B2O3-30SiO.sub.2.

9. The preparation method according to claim 7, wherein the preparation
of the luminescent substrate comprises: selecting a transparent or
translucent substrate as a substrate, and forming a luminescent film with
a chemical composition of Y2SiO5:Tb on the substrate.

10. A luminescence method of a luminescent element, comprising: obtaining
the luminescent element according to the preparation method of claim 7;
and emitting cathode-ray to the metal layer, and forming a surface
plasmon between the metal layer and the luminescent substrate by the
radiation of the cathode-ray and then irradiating the luminescent
substrate.

11. A luminescence method of a luminescent element, comprising: obtaining
the luminescent element according to the preparation method of claim 8;
and emitting cathode-ray to the metal layer, and forming a surface
plasmon between the metal layer and the luminescent substrate by the
radiation of the cathode-ray and then irradiating the luminescent
substrate.

12. A luminescence method of a luminescent element, comprising: obtaining
the luminescent element according to the preparation method of claim 9;
and emitting cathode-ray to the metal layer, and forming a surface
plasmon between the metal layer and the luminescent substrate by the
radiation of the cathode-ray and then irradiating the luminescent
substrate.

Description:

FIELD OF THE INVENTION

[0001] The present disclosure relates to luminescent materials, and more
particularly relates to a luminescent element including a glass substrate
made of luminescent material, preparation method thereof and luminescence
method.

BACKGROUND OF THE INVENTION

[0002] The conventional materials used as luminescent substrate include
phosphor, nanocrystal, glass, etc. Comparing to the crystal and phosphor,
the glass is transparent, rigid, and has excellent chemical stability and
superior luminescent performance. In addition, the glass can be easily
machined into products with various shapes, such as display devices or
luminescent light sources with various shapes and sizes.

[0003] For example, in vacuum microelectronics, field emission devices
usually use luminescent glass as illuminant, which has shown a wide
prospect in illumination and display techniques and draws a lot attention
to domestic and foreign research institutes. The working principle of the
field emission device is that, in vacuum, the anode applies a positive
voltage to the field emissive arrays (FEAs) to form an accelerating
electric field, electron emitted from the cathode accelerately bombards
the luminescent material on the anode plate to irradiate. The field
emission device has a wide operating temperature range (-40° C.
˜80° C.), short corresponding time (<1 ms), simple
structure, low energy consumption and meets the environmental protection
requirements. Furthermore, materials such as the phosphor, luminescent
glass, luminescent film, etc., can be served as luminescent material in
field emission device, however, they all suffer from serious problems of
low luminous efficiency, thus significantly limit the application of the
field emission device, especially in the application of illumination.

SUMMARY OF THE INVENTION

[0004] In one aspect of the present disclosure, a luminescent element with
a high luminescent homogeneity, high luminous efficiency, good stability,
simple structure and a preparation method with a simple processes and low
cost are desired.

[0005] In another aspect of the present disclosure, a luminescence method
of the luminescent element with simple operation, good reliability, and
high luminous efficiency is also desired.

[0006] A luminescent element includes: a luminescent substrate; and a
metal layer with a metal microstructure formed on a surface of the
luminescent substrate; wherein the luminescent substrate comprises a
luminescent material with a chemical composition of Y2SiO5:Tb.

[0007] A preparation method of a luminescent element includes:

[0008] preparing a luminescent substrate comprising a luminescent material
with a chemical composition of Y2SiO5:Tb;

[0009] forming a metal layer on the luminescent substrate, and

[0010] annealing the luminescent substrate and the metal layer in vacuum
to form a metal microstructure of the metal layer, and then cooling the
luminescent substrate and the metal layer to form the luminescent
element.

[0011] A luminescence method of a luminescent element includes:

[0012] obtaining the luminescent element according to the preparation
method described above; and

[0013] emitting cathode-ray to the metal layer, forming a surface plasmon
between the metal layer and the luminescent substrate by the radiation of
the cathode-ray and then irradiating the luminescent substrate.

[0014] In the luminescent element described above, the metal layer with a
metal microstructure is formed on a surface of the luminescent substrate,
and when irradiated by the cathode-ray, a surface plasmon can be formed
between the metal layer and the luminescent substrate. Due to the surface
plasmon effect, the internal quantum efficiency of the luminescent
substrate is highly increased, and the spontaneous emission of the
luminescent substrate is highly increased, so that the luminous
efficiency of the luminescent substrate is improved and the problem of
low efficiency of the luminescent materials is overcome. Accordingly, in
the luminescence method of the luminescent element, once emitting
cathode-ray to the metal layer, the surface plasmon will be formed
between the metal layer and the luminescent substrate, thus improving the
luminous efficiency and reliability. The luminescent element has a simple
two-layer structure for including the luminescent substrate and the metal
layer. In addition, there is a uniform interface formed between the
luminescent substrate and the metal layer, so that an excellent
luminescent homogeneity and stability is achieved. In the luminescence
method of the luminescent element, once emitting cathode-ray to the metal
layer, the surface plasmon will be formed between the metal layer and the
luminescent substrate, thus improving the luminous efficiency and
reliability of the luminescent substrate.

[0015] In the embodiment of the preparation method of the luminescent
element, the luminescent element can be obtained by forming a metal layer
on the luminescent substrate and annealing the luminescent substrate and
the metal layer, thus the preparation method is simple and has a low cost
and wide application prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The components in the drawings are not necessarily drawn to scale,
the emphasis instead being placed upon clearly illustrating the
principles of the present disclosure. Moreover, in the drawings, like
reference numerals designate corresponding parts throughout the views.

[0017] FIG. 1 is a schematic, side view of a luminescent element according
to an embodiment of the present disclosure;

[0018]FIG. 2 is a flowchart of an embodiment of a preparation method of a
luminescent element;

[0019] FIG. 3 is a flowchart of an embodiment of a luminescence method of
a luminescent element;

[0020] FIG. 4 is an emission spectrum of the luminescent element of
Example 1 comparing with the luminescent glass without the metal layer,
the emission spectrum being tested by a spectrometer excited by
cathode-ray of 5 KV accelerating voltage.

DETAILED DESCRIPTION

[0021] The disclosure is illustrated by way of example and not by way of
limitation in the figures of the accompanying drawings in which like
references indicate similar elements. It should be noted that references
to "an" or "one" embodiment in this disclosure are not necessarily to the
same embodiment, and such references mean at least one.

[0022] Referring to FIG. 1, an embodiment of a luminescent element 10
includes a luminescent substrate 13 and a metal layer 14 formed on a
surface of the luminescent substrate 13. The metal layer 14 has a metal
microstructure, which may be called as micro-nano structure. In addition,
the metal microstructure is aperiodic, i.e. composed of metal crystal in
irregular arrangement.

[0023] In one embodiment, the luminescent substrate 13 may be a
luminescent glass doped with the luminescent material with a chemical
composition of Y2SiO5:Tb. The luminescent glass has a
composition (by mole parts) of
20Na2O-20BaO-30B2O3-30SiO2, which is not limited if
glass powder with low melting temperature is used. The luminescent
material of Y2SiO5:Tb is 5%˜35% by weight of the
luminescent substrate.

[0024] In an alternative embodiment, the luminescent substrate 13 includes
a transparent or translucent substrate and a luminescent film formed on
the substrate with a chemical composition of Y2SiO5:Tb, and the
metal layer 14 is formed on a surface of the luminescent film.

[0025] The metal layer 14 may be made of metals with excellent chemical
stability, such as antioxidant and corrosion-resistant metals, or common
metals. The metal layer 14 is preferably made of at least one metal
selected from the group consisting of Au, Ag, Al, Cu, Ti, Fe, Ni, Co, Cr,
Pt, Pd, Mg, and Zn, or more preferably made of at least one metal
selected from the group consisting of Au, Ag, and Al. The metal layer 14
may be made of one metal or a composite metal. The composite metal may be
an alloy of two or more than two metals described above. For example, the
metal layer 14 may be an Ag/Al alloy layer or an Au/Al alloy layer, where
the weight percent of Ag or Au is preferably more than 70%. The metal
layer 14 has a thickness in a range of 0.5˜200 nm, preferably
1˜100 nm.

[0026] As a luminescent element, the luminescent element 10 can be widely
applied to luminescent devices with ultra-high brightness and high-speed
motion, such as field emission display, field emission light source, and
large advertising display, etc. Take field emission display as an
example, the anode applies a positive voltage to the field emission
cathode to form an accelerating electric field, the cathode emits
electron, i.e. cathode-ray 16 to the metal layer 14, so that a surface
plasmon is formed between the metal layer 14 and the luminescent
substrate 13. Due to the surface plasmon effect, the internal quantum
efficiency of the luminescent substrate 13 is highly increased, and the
spontaneous emission of the luminescent glass is highly increased, so
that the luminous efficiency of the luminescent glass is improved and the
problem of low efficiency of the luminescent materials is overcome. In
addition, since a metal layer is formed on the surface of the luminescent
substrate 13, a uniform interface is formed between the whole metal layer
and the luminescent substrate 13, thus improving the luminescent
homogeneity.

[0027] Referring to FIG. 1 and FIG. 2, a flow chart of an embodiment of a
preparation method of a luminescent element includes following steps:

[0028] Step S01, the luminescent substrate 13 is prepared. The luminescent
substrate 13 includes a luminescent material with a chemical composition
of Y2SiO5:Tb.

[0029] Step S02, the metal layer 14 is formed on a surface of the
luminescent substrate 13.

[0030] Step S03, the luminescent substrate 13 and the metal layer 14 are
annealed in vacuum to form a metal microstructure of the metal layer, and
then the luminescent substrate 13 and the metal layer 14 are cooled to
form the luminescent element.

[0031] In the step S01, the luminescent substrate 13 accordingly has two
types of structure, the first one is the luminescent glass doped with the
luminescent material with a chemical composition of Y2SiO5:Tb,
and the second one includes a substrate and a luminescent film of
Y2SiO5:Tb formed on the substrate. The preparation of the first
type of the luminescent substrate 13 includes: mixing the luminescent
material of Y2SiO5:Tb and glass powder, melting the luminescent
material of Y2SiO5:Tb and glass powder at a temperature in a
range of 1000˜1300° C.; cooling the luminescent material of
Y2SiO5:Tb and glass powder to ambient temperature, and
obtaining the luminescent glass doped with the luminescent material of
Y2SiO5:Tb, wherein the luminescent glass has a composition of
20Na2O-20BaO-30B2O3-30SiO2. In detail, The
luminescent material of Y2SiO5:Tb in the form of powder is
mixed with glass powder at a weight ratio of 1:19˜7˜13, so
that the luminescent material of Y2SiO5:Tb is 5%˜35% by
weight of the mixture. The mixture is then melt at a temperature of
1000˜1300° C. and cooled to ambient temperature by pouring
on a steel plate, and the luminescent substrate 13 is finally obtained.
The melting temperature is preferably 1200° C.

[0032] The preparation of the second type of the luminescent substrate 13
includes: selecting a transparent or translucent substrate as a
substrate, and forming a luminescent film with a chemical composition of
Y2SiO5:Tb on the substrate. The luminescent film of
Y2SiO5:Tb may be deposited on the substrate by magnetron
sputtering, electron beam evaporation, chemical vapor deposition,
molecular beam epitaxy, pulsed laser deposition, or spray pyrolysis, etc.

[0033] As previously described, the metal layer 14 is formed by depositing
metal source with excellent chemical stability, such as antioxidant and
corrosion-resistant metals, or common metals. The metal layer 14 is
preferably made of at least one metal selected from the group consisting
of Au, Ag, Al, Cu, Ti, Fe, Ni, Co, Cr, Pt, Pd, Mg, and Zn, or more
preferably made of at least one metal selected from the group consisting
of Au, Ag, and Al. In step S02, the metal layer 14 is formed on the
surface of the luminescent substrate 13 via PVD or CVD, for example, via
sputtering or evaporation, with at least one metal described above. The
metal layer 14 has a thickness in a range of 0.5˜200 nm, preferably
1˜100 nm.

[0034] In step S03, after the formation of the metal layer 14 on the
luminescent substrate 13, the metal layer 14 and the luminescent
substrate 13 are annealed at a temperature in a range of
50˜650° C. for a period of time of 5 minutes to 5 hours and
cooled to ambient temperature. The preferred anneal temperature is in a
range of 100˜500° C., and the preferred anneal time is in a
range of 15 minutes to 3 hours.

[0035] Referring to FIG. 1 and FIG. 3, a flow chart of a luminescence
method of the luminescent element includes following steps:

[0036] Step S11, the luminescent element 10 is obtained according to the
previously described preparation method.

[0037] Step S12, the cathode-ray 16 is emitted to the metal layer 14. A
surface plasmon is formed between the metal layer 14 and the luminescent
substrate 13 by the radiation of the cathode-ray 16 and thus irradiating
the luminescent substrate 13.

[0038] The luminescent element 10 has features of structure and
composition as previously described. In application, the step S12 can be
implemented by field emission display or illumination light source. In
vacuum, the anode applies a positive voltage to the field emission
cathode to form an accelerating electric field, so that the cathode emits
cathode-ray 16. Excited by the cathode-ray 16, electron beam will
penetrate the metal layer 14 and irradiate the luminescent substrate 13.
During such process, a surface plasmon is formed between the metal layer
14 and the luminescent substrate 13. Due to the surface plasmon effect,
the internal quantum efficiency of the luminescent substrate 13 is highly
increased, and the spontaneous emission of the luminescent material is
highly increased, so that the luminous efficiency of the luminescent
material is improved.

[0039] As previously described, the luminescent substrate 13 accordingly
has two types of structure. In the first type, the electron beam will
penetrate the metal layer 14 and irradiate the luminescent material of
Y2SiO5:Tb in the luminescent glass, and the surface plasmon is
formed between the surface of the luminescent glass doped with the
luminescent material of Y2SiO5:Tb and the metal layer 14, thus
irradiating the luminescent material of Y2SiO5:Tb. In the
second type, the electron beam will penetrate the metal layer 14 and
irradiate the luminescent film of Y2SiO5:Tb directly, and the
surface plasmon is formed between the luminescent film of
Y2SiO5:Tb and the metal layer 14, thus irradiating the
luminescent film of Y2SiO5:Tb.

[0040] Surface plasmon (SP) is a wave spread along the interface between
the metal and medium, whose amplitude exponentially decay with the
increase of the distance away from the interface. When changing a surface
structure of the metal, the feature, dispersion relationship, excitation
mode, coupling effect of the surface plasmon polaritons (SPPs) will be
significantly changed. The electromagnetic field caused by the SPPs can
not only constrain the spread of the light wave in sub-wavelength size
structure, but also can produce and manipulate the electromagnetic
radiation from light frequency to microwave band, thus active
manipulation of the light spread is implemented. Accordingly, the present
embodiment uses the excitation of the SPPs to increase the optical
density of the luminescent glass and to enhance spontaneous emission
velocity of the luminescent glass. In addition, the coupling effect of
the surface plasmon can be used, when the luminescent glass irradiates,
sympathetic vibration phenomena occurs, thus the internal quantum
efficiency of the luminescent glass is highly increased, so that the
luminous efficiency of the luminescent glass is improved.

[0041] A plurality of examples are described to illustrate the different
compositions and preparation methods of the luminescent element, and
their performances. In the examples, Y2SiO5:Tb can be utilized
from a commercial product.

EXAMPLE 1

[0042] Phosphor with the composition of Y2SiO5:Tb is mixed with
glass powder with the composition of
20Na2O-20BaO-30B2O3-30SiO2 in a weight ratio of 1:4,
and the mixture is melt to obtain the luminescent glass doped with the
luminescent material of Y2SiO5:Tb. A silver layer with a
thickness of 2 nm is deposited on the surface of the luminescent glass
via a magnetron sputtering equipment. The luminescent substrate and the
silver layer are annealed at a temperature of 300° C. for half an
hour in vacuum with the vacuum degree <1×10-3 Pa and cooled
to ambient temperature, thus a luminescent element is obtained.

[0043] During the spectroscopy test, the prepared luminescent element is
bombarded by cathode-ray emitted from an electron gun, and the electron
beam penetrates the metal layer and irradiates the luminescent glass
doped with the luminescent material of Y2SiO5:Tb, thus an
emission spectrum shown in FIG. 4 is obtained, which shows that the
luminescent material emits green light. In FIG. 4, curve 11 represents an
emission spectrum of a luminescent glass without the metal layer; curve
12 represents an emission spectrum of the luminescent element with the
metal layer of Example 1. As shown in FIG. 4, since a surface plasmon is
formed between the metal layer and the luminescent glass, comparing to
the luminescent glass without the metal layer, the luminescent element
with the metal layer of Example 1 has a luminescence integral intensity 4
times as that of the luminescent glass without the metal layer in a
wavelength of 350˜700 nm, accordingly, the luminescent performance
is greatly improved.

[0044] Other Examples have the similar emission spectrums and luminescent
performance as Example 1, which will not be described later.

EXAMPLE 2

[0045] Phosphor with the composition of Y2SiO5:Tb is mixed with
glass powder with the composition of
20Na2O-20BaO-30B2O3-30SiO2 in a weight ratio of 1:19,
and the mixture is melt to obtain the luminescent glass doped with the
luminescent material of Y2SiO5:Tb. A gold layer with a
thickness of 0.5 nm is deposited on the surface of the luminescent glass
via a magnetron sputtering equipment. The luminescent substrate and the
gold layer are annealed at a temperature of 200° C. for one hour
in vacuum with the vacuum degree <1×10-3 Pa and cooled to
ambient temperature, thus a luminescent element is obtained.

EXAMPLE 3

[0046] Phosphor with the composition of Y2SiO5:Tb is mixed with
glass powder with the composition of
20Na2O-20BaO-30B2O3-30SiO2 in a weight ratio of 7:13,
and the mixture is melt to obtain the luminescent glass doped with the
luminescent material of Y2SiO5:Tb. An aluminum layer with a
thickness of 200 nm is deposited on the surface of the luminescent glass
via a magnetron sputtering equipment. The luminescent glass and the
aluminum layer are annealed at a temperature of 500° C. for 5
hours in vacuum with the vacuum degree <1×10-3 Pa and
cooled to ambient temperature, thus a luminescent element is obtained.

EXAMPLE 4

[0047] A 1×1 cm2, double-sided polished, sapphire substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A magnesium layer with a thickness of 100 nm is deposited on the surface
of the luminescent glass via an electron beam evaporation equipment. The
luminescent substrate and the magnesium layer are annealed at a
temperature of 650° C. for 5 minutes in vacuum with the vacuum
degree <1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 5

[0048] A 1×1 cm2, double-sided polished, magnesium oxide
substrate is selected, and a luminescent film with the chemical
composition of Y2SiO5:Tb is formed on the substrate via
molecular beam epitaxy. A palladium layer with a thickness of 1 nm is
deposited on the surface of the luminescent glass via an electron beam
evaporation equipment. The luminescent glass and the palladium layer are
annealed at a temperature of 100° C. for 3 hours in vacuum with
the vacuum degree <1×10-3 Pa and cooled to ambient
temperature, thus a luminescent element is obtained.

EXAMPLE 6

[0049] A 1×1 cm2, double-sided polished, magnesium oxide
substrate is selected, and a luminescent film with the chemical
composition of Y2SiO5:Tb is formed on the substrate via spray
pyrolysis. A platinum layer with a thickness of 5 nm is deposited on the
surface of the luminescent glass via an electron beam evaporation
equipment. The luminescent glass and the platinum layer are annealed at a
temperature of 450° C. for 15 minutes in vacuum with the vacuum
degree <1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 7

[0050] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
An iron layer with a thickness of 20 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the iron layer are annealed at a temperature of
50° C. for 5 hours in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 8

[0051] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A titanium layer with a thickness of 10 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the titanium layer are annealed at a temperature of
150° C. for 2 hours in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 9

[0052] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A copper layer with a thickness of 50 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the copper layer are annealed at a temperature of
200° C. for 2.5 hours in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 10

[0053] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A zinc layer with a thickness of 150 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the zinc layer are annealed at a temperature of
350° C. for 0.5 hour in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 11

[0054] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A chromium layer with a thickness of 120 nm is deposited on the surface
of the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the chromium layer are annealed at a temperature of
250° C. for 2 hours in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 12

[0055] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A nickel layer with a thickness of 40 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the nickel layer are annealed at a temperature of
80° C. for 4 hours in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 13

[0056] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A cobalt layer with a thickness of 180 nm is deposited on the surface of
the luminescent glass via an electron beam evaporation equipment. The
luminescent glass and the cobalt layer are annealed at a temperature of
400° C. for 1 hour in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 14

[0057] Phosphor with the composition of Y2SiO5:Tb is mixed with
glass powder with the composition of
20Na2O-20BaO-30B2O3-30SiO2 in a weight ratio of 3:17,
and the mixture is melt to obtain the luminescent glass doped with the
luminescent material of Y2SiO5:Tb. A gold/aluminum layer with a
thickness of 0.5 nm is deposited on the surface of the luminescent glass
via an electron beam evaporation equipment. In the gold/aluminum layer,
the gold is about 80 weight %, and the aluminum is about 20 weight %. The
luminescent glass and the gold/aluminum layer are annealed at a
temperature of 200° C. for 1 hour in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 15

[0058] Phosphor with the composition of Y2SiO5:Tb is mixed with
glass powder with the composition of
20Na2O-20BaO-30B2O3-30SiO2 in a weight ratio of 3:7,
and the mixture is melt to obtain the luminescent glass doped with the
luminescent material of Y2SiO5:Tb. A silver/aluminum layer with
a thickness of 15 nm is deposited on the surface of the luminescent glass
via a magnetron sputtering equipment. In the silver/aluminum layer, the
silver is about 90 weight %, and the aluminum is about 10 weight %. The
luminescent glass and the silver/aluminum layer are annealed at a
temperature of 200° C. for 1 hour in vacuum with the vacuum degree
<1×10-3 Pa and cooled to ambient temperature, thus a
luminescent element is obtained.

EXAMPLE 16

[0059] A 1×1 cm2, double-sided polished, quartz substrate is
selected, and a luminescent film with the chemical composition of
Y2SiO5:Tb is formed on the substrate via magnetron sputtering.
A silver/aluminum layer with a thickness of 10 nm is deposited on the
surface of the luminescent glass via an electron beam evaporation
equipment. In the silver/aluminum layer, the silver is about 80 weight %,
and the aluminum is about 20 weight %. The luminescent glass and the
silver/aluminum layer are annealed at a temperature of 150° C. for
2 hours in vacuum with the vacuum degree <1×10-3 Pa and
cooled to ambient temperature, thus a luminescent element is obtained.

EXAMPLE 17

[0060] A 1×1 cm2, double-sided polished, magnesium oxide
substrate is selected, and a luminescent film with the chemical
composition of Y2SiO5:Tb is formed on the substrate via
magnetron sputtering. A gold/aluminum layer with a thickness of 0.5 nm is
deposited on the surface of the luminescent glass via a magnetron
sputtering equipment. In the gold/aluminum layer, the gold is about 90
weight %, and the aluminum is about 10 weight %. The luminescent glass
and the gold/aluminum layer are annealed at a temperature of 120°
C. for 2 hours in vacuum with the vacuum degree <1×10-3 Pa
and cooled to ambient temperature, thus a luminescent element is
obtained.

[0061] In Examples described above, the metal layer 14 with a metal
microstructure is formed on a surface of the luminescent substrate 13,
and when irradiated by the cathode-ray, a surface plasmon can be formed
between the metal layer 14 and the luminescent substrate 13. Due to the
surface plasmon effect, the internal quantum efficiency of the
luminescent substrate 13 is highly increased, and the spontaneous
emission of the luminescent glass is highly increased, so that the
luminous efficiency of the luminescent glass is improved and the problem
of low efficiency of the luminescent materials is overcome. In the
luminescence method of the luminescent element, once emitting cathode-ray
to the metal layer 14, the surface plasmon will be formed between the
metal layer 14 and the luminescent substrate 13, thus improving the
luminous efficiency and reliability. The luminescent element 10 has a
simple two-layer structure for including the luminescent substrate 13 and
the metal layer 14. In addition, there is a uniform interface formed
between the luminescent substrate 13 and the metal layer 14, so that an
excellent luminescent homogeneity and stability is achieved. In the
luminescence method of the luminescent element, once emitting cathode-ray
to the metal layer 14, the surface plasmon will be formed between the
metal layer 14 and the luminescent substrate 13, thus improving the
luminous efficiency and reliability of the luminescent substrate 13.

[0062] In the embodiment of the preparation method of the luminescent
element, the luminescent element can be obtained by forming a metal layer
14 on the luminescent substrate 13 and annealing the luminescent
substrate 13 and the metal layer 14, thus the preparation method is
simple and has a low cost. The luminescent element can be widely applied
to luminescent devices with ultra-high brightness and high-speed motion,
such as field emission display.

[0063] Although the invention has been described in language specific to
structural features and/or methodological acts, it is to be understood
that the invention defined in the appended claims is not necessarily
limited to the specific features or acts described. Rather, the specific
features and acts are disclosed as sample forms of implementing the
claimed invention.